[Hampshire] Changing user passwords without shell access

Hi,

I have a number of users who have CVS/pserver access to a machine but who
do not have shell login privileges on the machine.

I'd like a way to let them set/change their own passwords (currently I'm
having to create and distribute passwords when I create the account)
without actually giving them the ability to login to the server.

The server also runs apache so some sort of web interface would be
possible, however the solution doesn't have to be web based it just
requires that the users have a means to change passwords without gaining
access to a bash (or any other shell) prompt.

Any suggestions on a way to achieve this?

Andy